1. Technical Field
The present invention relates to a pattern analysis system, and more particularly, to a mask pattern analysis system and a mask pattern analysis method in order to facilitate semiconductor lithography processes.
2. Background
As optical lithography advances into the 90 nm technology node and beyond, minimum feature size outpaces the introduction of advanced lithography hardware solutions. Optical proximity correction (OPC) is a widely used resolution enhancement technique for control of critical dimension. With OPC, photomask shapes are deliberately distorted to compensate for different amounts of pattern information diffracted at various pitches. The data generated by the OPC is then typically imported into a simulation tool, to confirm whether the OPC will have the desired corrective effect; this is sometimes called an optical and process rule check, or ORC. ORC is an important vehicle to predict the failure of pattern shapes and to check post-OPC aerial images against drawn shapes. If not aided by ORC, OPC may cause severe failures affecting the yield in manufacturing.
However, it is fairly time-consuming to conduct an ORC across the wafer if the aerial images are reviewed one by one. ORC can be run before OPC to determine if OPC is even necessary, at an intermediate point in an OPC run to determine if the results are good enough, or after OPC has been completed. Once this check is complete, the data is exported for use in IC manufacturing process. Typically, areas detected with bridging or pinching phenomenon are highlighted and subsequently reverted to OPC for further mask correction.
To solve the problem of excessive time consumption in the ORC step, a more systematic review method is required. An efficient ORC step is crucial to an efficient mask production process, which is expected to face more challenges with the decrease of technology node and the increase of the device density per chip.